B-Hebrew: The Biblical Hebrew Forum

We read there
אוֹ בִשְׁתִי אוֹ בְעֵרֶב לַפִּשְׁתִּים וְלַצָּמֶר
KJV: "Whether it be in the warp, or woof; of linen, or of woollen"
But why is the letter T of בִשְׁתִי dageshless? I think that when the dagesh was introduced (a millennium prior to the nikud?) into the biblical text to facilitate the correct reading, the reading of the letter B was not as now with a xireq.

Isaac Fried, Boston University

The name שתי from the root שת (assuming that the letter ת is indeed radical and not the PP את) is kindred with the שֵׁת, 'addenda', of Isaiah 20:4
כֵּן יִנְהַג מֶלֶךְ אַשּׁוּר אֶת שְׁבִי מִצְרַיִם וְאֶת גָּלוּת כּוּשׁ נְעָרִים וּזְקֵנִים עָרוֹם וְיָחֵף וַחֲשׂוּפַי שֵׁת עֶרְוַת מִצְרָיִם

Isaac Fried, Boston University

Also related is the act ישט YA$AT, 'stretch out, extend', as in Esther 4:11
לְבַד מֵאֲשֶׁר יוֹשִׁיט לוֹ הַמֶּלֶךְ אֶת שַׁרְבִיט הַזָּהָב
NIV: "unless the king extends the gold scepter to them"

Isaac Fried, Boston University